50 lines
1.6 KiB
JavaScript
50 lines
1.6 KiB
JavaScript
import { Observable } from '../Observable';
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import { noop } from '../util/noop';
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/**
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* We need this JSDoc comment for affecting ESDoc.
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* @extends {Ignored}
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* @hide true
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*/
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export class NeverObservable extends Observable {
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constructor() {
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super();
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}
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/**
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* Creates an Observable that emits no items to the Observer.
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*
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* <span class="informal">An Observable that never emits anything.</span>
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*
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* <img src="./img/never.png" width="100%">
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*
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* This static operator is useful for creating a simple Observable that emits
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* neither values nor errors nor the completion notification. It can be used
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* for testing purposes or for composing with other Observables. Please note
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* that by never emitting a complete notification, this Observable keeps the
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* subscription from being disposed automatically. Subscriptions need to be
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* manually disposed.
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*
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* @example <caption>Emit the number 7, then never emit anything else (not even complete).</caption>
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* function info() {
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* console.log('Will not be called');
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* }
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* var result = Rx.Observable.never().startWith(7);
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* result.subscribe(x => console.log(x), info, info);
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*
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* @see {@link create}
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* @see {@link empty}
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* @see {@link of}
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* @see {@link throw}
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*
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* @return {Observable} A "never" Observable: never emits anything.
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* @static true
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* @name never
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* @owner Observable
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*/
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static create() {
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return new NeverObservable();
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}
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/** @deprecated internal use only */ _subscribe(subscriber) {
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noop();
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}
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}
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//# sourceMappingURL=NeverObservable.js.map
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